Transcript UNIT V File

Geographic Information System
(GIS)
Submitted by
M .U. Kale
Assistant professor
Irrigation & Drainage Engineering
Dr. P.D.K.V. Akola
Geographic Information System (GIS)
 A Geographic Information System (GIS) can be
defined as a computer-based system for the
digital entry, storage, transformation, analysis,
and display of spatial data.
Fundamentals of GIS.
• Database Query:
select various combinations of variables for
examination
• Queries are of two types
I. queries of location (What occurs in this
location?)
II. queries of attribute (Where are the areas in
which attribute occurs?)
• Derivative Mapping
we combine selected components of our
database to yield new derivative layers.
• Process Modeling
It is a third area that is receiving increasing
attention -- process or simulation modeling.
Components of GIS
Application and need of GIS
• GIS is one of many tools that may be
used to solve problems
• The decision about whether to use a GIS
is complex.
• GIS
results
efficiency.
in
appropriateness
and
Introduction to arc view GIS
• Most popular desktop GIS analysis and map
presentation software package.
• Create intelligent, dynamic maps using data from
numerous sources.
• Includes tools and data.
• We can use out-of the- box to perform state-of-the-art
analysis on key issues.
Main features of Arc View
• It can access and link documents, images,
tables, text, graphics, spreadsheets, maps,
multimedia, and CAD drawings in an
integrated and comprehensive way.
• It provides routine display and plotting of
collection system maps and querying the GIS
database.
• Helps to quickly select and display different
combinations
of
data
for
creative
visualization of mapping data.
Main features of Arc View
• Directly use AutoCAD drawings (DWG files) or AutoCAD interchange
files (DXF files).
•
Link map information to SQL databases which are common in local
governments, such as: ORACLE, INGRES, INFORMIX, and SYGIS
data can be explored and retrieved by selecting features or
formulating logical expressions.
• GIS BSE Arc View provides editing tools for creating new maps and
modifying existing ones.
•
Arc View is very user-friendly and provides context sensitive on-line
help
Limitations
• A limitation of Arc View is that it is not
intended to support a GIS production shop.
• The paper maps cannot be digitized directly
in Arc View.
• Arc View has limited feature editing capability
Decision support system
• Decision support systems (DSS) are developed
to assist decision-makers.
• Decision support systems are like the central
nervous system connecting the operational
entities to the brain.
Components of DSS
• Access to data and data output (maps, reports)
• Access to GIS analysis (e.g. overlay and
proximity analysis)
• Access to models or rule-based "expert"
information
• Methods to account for and display error and
uncertainty
• Logging and tracking methods to document
the decision process
• Methods to evaluate alternative scenarios /
trade-offs.
Spatial Decision Support System (SDSS)
• SDSS is an interactive, computer-based system
designed to support a user or group of users in
achieving a higher effectiveness of decision
making while solving a semi-structured spatial
decision problem
Principles of SDSS
• The DDM paradigm - the technology for a DSS
must consist of three sets of capabilities in the
areas of dialog, data, and modeling (the DDM
paradigm) (Sprague and Watson, 1996);
• A well-design SDSS should have balance
among the three capabilities.
Components of SDSS
Functions of SDSS
• The Data Base Management System (DBMS)
contains the functions to manage the geographic
data base;
• The Model Base Management System (MBMS)
contains the functions to manage the model base;
• The Dialog Generation and Management System
(DGMS) manages the interface between the user
and the rest of the system.
Thank you!